In March, the controlling shareholders of Fibria accepted an $11 billion bid by Suzano, in a deal to create the world’s biggest pulp producer.

The Tempo complaint, filed on June 11, said the acquisition should have triggered a mandatory tender offer for minority shareholders, according to the paper, citing documents filed with the regulator that are not made public.

The regulator told Reuters that a complaint had been filed by Tempo Capital against Fibria on June 11, but did not confirm if it related to the purchase by Suzano.

The fund accuses the controlling shareholders of abusing their voting power to close the deal, Valor said. The cash part of the deal will be adjusted by interest rates only for controlling shareholders and not for minority shareholders, it said.

Suzano said it did not comment on “ongoing processes” and Fibria declined to comment. Representatives for Tempo Capital could not be reached.